package edu.scau.mis.core.config;


import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.parser.ParserConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.TypeFactory;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.SerializationException;
import org.springframework.util.Assert;

import java.nio.charset.Charset;

/**
 * Lettuce 底层使用Netty，所以一定需要进行序列化配置。因此需要缓存的类，必须要实现Serializable接口。
 * Redis使用FastJson序列化
 * Jackson不能为没有无参构造方法类进行反序列化
 * 解决SpringSecurity的没有无参构造方法的SimpleGrantedAuthority反序列化问题
 * 参照Jackson2JsonRedisSerializer
 */
public class FastJson2JsonRedisSerializer<T> implements RedisSerializer<T> {
    @SuppressWarnings("unused")
    private ObjectMapper objectMapper = new ObjectMapper();
    public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

    private Class<T> clazz;
    static{
        ParserConfig.getGlobalInstance().setAutoTypeSupport(true);
    }

    public FastJson2JsonRedisSerializer(Class<T> clazz){
        super();
        this.clazz = clazz;
    }

    @Override
    public byte[] serialize(T t) throws SerializationException{
        if (t == null){
            return new byte[0];
        }
        return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(DEFAULT_CHARSET);
    }

    @Override
    public T deserialize(byte[] bytes) throws SerializationException{
        if (bytes == null || bytes.length <= 0) {
            return null;
        }
        String str = new String(bytes, DEFAULT_CHARSET);
        return JSON.parseObject(str, clazz);
    }

    public void setObjectMapper(ObjectMapper objectMapper){
        Assert.notNull(objectMapper, "'objectMapper' must not be null");
        this.objectMapper = objectMapper;
    }

    protected JavaType getJavaType(Class<?> clazz) {
        return TypeFactory.defaultInstance().constructType(clazz);
    }
}

